CHICAGO (CBS) — A Megabus headed from Chicago to Atlanta crashed about 30 miles south of Indianapolis early Monday, injuring at least 19 people.

Indiana State Police said the bus crashed into the back of a semi-tractor trailer on I-65, near Edinburgh, Indiana, around 6 a.m. eastern time. The truck had stopped because of construction, and the bus did not stop quickly enough to avoid a crash. The collision pushed the truck into two passenger vehicles.

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“It was really scary. When it first hit … the whole front of the bus is glass, and so everything shattered, and there’s people sitting right up there, so I thought that there was people that could have gone through the window, but thankfully no one did,” passenger Rachel Stringer said.

There were 63 passengers on the bus at the time, and 19 of them were taken to hospitals, but none of the injuries was considered serious. No one in the other three vehicles was injured.

“Safety is our number one priority and Megabus is fully cooperating with the authorities with their investigation into the incident,” Megabus spokesman Sean Hughes said in an email.

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Police said the bus driver was given a breath test for alcohol, and the results were negative, ruling out alcohol as a factor in the crash.

Public buses from Indianapolis were brought in to transport the uninjured passengers off the highway, to a safe location.

Police said the bus would undergo a thorough inspection, to determine if any mechanical problems contributed to the crash.

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The crash site is about 20 miles south from where another Megabus crashed near Greenwood, Indiana, in October, injuring at least 18 people.